This is a Mauser machine gun and uses the Mauser cartridge (7.92x57mm) and is suited for general-purpose. It was created in Nazi Germany and was heavily used by the Waffen-SS and Wehrmacht at the end of World War 2. It was initially made to replace the Mg-34 as it was cheaper to manufacture as well as quicker to make too, but in the end, both machine guns remained in production throughout the War.
The MG-42 machine gun has been proven to be reliable, durable, simple and easy to use and is most handy in that it can produce a higher than usual volume of suppressive fire. It could average between 1,200 and 1,500 rounds per minute which was fantastic for this type of gun.
This gun was still being used beyond the War ending and was the basis for the later MG1, which was almost identical to the MG-42, which took 7.62x51mm NATO chambers. This then evolved to the MG1A3 and then eventually the Bundeswehr MG-3.